Can tea help prevent type 2 diabetes?

Drinking tea every day might help to prevent type 2 diabetes through better blood sugar control, research has shown.

A 2023 study of nearly 2,000 people in China found that people who drank tea – including green, builder’s and other types – every day reduced their risk of type 2 diabetes by 28%, compared with those who never had a cuppa.

The biggest benefits came from Chinese dark tea: people who drank it every day saw a 47% reduced risk of type 2 diabetes.

The researchers from the University of Adelaide in Australia and China’s Southeast University suggest this could be due to the way dark tea is produced – it’s fermented for longer using ancient techniques and can be stored for years.

Milk and two sugars? Not exactly

More than 13 million people in the UK are at risk of developing type 2 diabetes, which is much more common than type 1. But research shows that making changes to your lifestyle can help to prevent type 2 diabetes – and even reverse it.

Previous studies have suggested that high levels of caffeine in your blood could cut your risk of developing diabetes, so you can add your daily cup of tea to your list of positive lifestyle changes.

Co-lead author of the study Professor Zilin Sun, from Southeast University in China, said: “Our findings suggest that drinking dark tea every day has the potential to lessen type 2 diabetes risk and progression through better blood sugar control. It may be one simple step people can easily take to improve their diet and health.”

Sophie Medlin, consultant dietitian at CityDietitians, told Saga: “Tea is full of phytochemicals called polyphenols, which have a positive impact on our health, including having anti-inflammatory benefits.

“Increasingly, diabetes and cardiovascular disease are seen as having inflammatory roots. Polyphenols are also known to support our gut microbiome positively.”

But she cautions that drinking tea isn’t the only step you need to take to reduce your risk of type 2 diabetes.

“Unfortunately, I’m sure we all know people who are avid tea drinkers but still live with diabetes, so it’s important to make other lifestyle changes too.

"When we look at studies that are done on populations with very different eating and lifestyle habits to our own – such as this one in China – we have to take the evidence and contextualise it within a Western population, which is very different.

“This study is useful and interesting, but we don’t want the take-home message to be that drinking tea can prevent or reverse diabetes without any other necessary lifestyle changes within the context of Western diets and lifestyles.

"But it’s definitely a good reason to keep having your cup of tea – without sugar, of course.”

Eat well to prevent type 2 diabetes

So what other steps can you take to reduce your risk of developing type 2 diabetes?

Diabetes UK recommends moving more – such as with a brisk walk, or another exercise that leaves you a little out of breath, for 30 minutes five times a week, or three ten-minute bursts if you’re short of time.

Maintaining a healthy weight, limiting the amount of alcohol you drink and avoiding smoking can also help to reduce your risk.

Eating well is key and Diabetes UK has the following guidance:

• Cut down on sugary and fizzy drinks – Choose drinks without added sugar, replace fruit juices and smoothies with plain water or milk – and don’t have sugar in your tea and coffee.
• Eat more fibre – Swap white bread, white rice and sugary breakfast cereals for wholewheat versions and oats.
• Cut down on red and processed meat – Swap ham, bacon and sausages for eggs, fish, chicken and turkey; and add beans and lentils to your meals. Include healthy fats from seeds, avocados and olive oil.
• Eat plenty of fruit and vegetables – Apples, grapes, berries and green leafy vegetables such as spinach, kale, watercress and rocket are good.
• Go for unsweetened yogurt and cheese – Choose plain milk and Greek yogurt – plus fermented dairy products have been linked with a reduced risk of type 2 diabetes.
• Grab a healthy snack – Seeds, unsalted nuts, fruit and vegetables beat chips, crisps and biscuits.
• Cut down on salt – Eating lots of salt can increase your risk of high blood pressure, which can also lead to an increased risk of type 2 diabetes.